If it's still lagging, you're gonna have to play on Low.. although that's a big self-explanatory. Long-story-short, turn off all options.

Click to expand...

Definitely turn off motion blur. Maybe you can ramp up the settings as soon as AMD releases 13.2 since it improves Far Cry 3 performance. But the problem is that AMD usually optimises higher end cards like >7750, they dont really focus on lower end cards. If anything, maybe a small increase, but the drivers for low end cards are usually bug fixes.